PPRuNe Forums - View Single Post - Sikorsky S-76: Ask Nick Lappos
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Old 26th Oct 2004, 02:37
  #488 (permalink)  
IHL
 
Join Date: Feb 2001
Location: Canada
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On the 250 C-30S engine it is not uncommon. The engine manufacturer won't acknowledge the problem.

It was a standing joke where I worked. Every time there was an engine change we would get compressor stall/popping/surge, when conducting the engine stall check.

The engineers would call the tech rep.
They would suggest: And the drill went something like this:
Try it with the AI and heater on, done,
Change the Bleedvalve, done
change the FCU, done

Then they would send the tech rep and tweak the N1 nozzle and then it would be fine; until the temperature dropped.

The engine guys told me that the test cell does not do a very good job of replecating the engine intakes of the 76. Therefore it would test fine in the test cell but fail the stall check in the aircraft.
(the stall check [from memory] was to advance the throttle from idle to full throttle and then back within a couple of seconds, the check would also test the blade dampers during acceleration and deceleration).

Once the engine spooled up there was never any problem with power.
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